Project: COMPASS - Synoptic Chesapeake Bay

Data Type: Tree Gas Well GHGs (TGAS)

Sampling Type: Greenhouse gas concentrations

Sampling Locations: COMPASS Synoptic Sites: MSM, GWI, GCW Trees


Data Description: These data are from tree gas wells (installed after coring trees at the synoptic sites). The gas wells were capped with rubber stoppers and allowed to equilibrate then sampled with a needle and syringe to collect a gas sample from the tree. The sample volume is dependent on the gas well size (see protocols within each year for details). The samples were stored in exetainers then analyzed for methane and carbon dioxide on a Varian 450 Gas Chromatograph. The methane is determined with an FID and the carbon dioxide with a TCD.

Figure 1: Gas well example and sample collection
Figure 1: Gas well example and sample collection


Samples were collected from the Moneystump (MSM), Goodwin Islands (GWI), and GCW (GCReW) synoptic sites. The sapflow trees at these sites in the Upland (UP) and Transition (TR) zones had gas wells and there were also some dead standing trees cored and sampled as well at MSM and GWI. The GCW UP samples overlap with the TEMPEST experiment control plot, so to get the GCW UP and TR data it may also need to be pulled from the TEMPEST page.


Figure 2: Experimental design
Figure 2: Experimental design


Gas samples were collected roughly from May to November at each site during 2022 and 2023. Sampling these wells was discontinued in 2024.

For questions about this data: contact Stephanie J. Wilson () or Patrick Megonigal ().

Data Files Available:

“COMPASS_SynopticCB_TGAS_AllData.csv” = All data from all years.QAQC’d and collated.

“COMPASS_SynopticCB_TGAS_Metadata.csv” = Metadata for AllData file that explains each column header, units, and instrumentation.